JPS5822938A - Automatic reader of brinell hardness meter - Google Patents

Abstract

PURPOSE:To generate a picture quality whose S/N is excellent, even if a condenser lens is small, and to execute a measurement with high accuracy by a simple picture processing system, by providing an ignition source on a focus of an impression surface. CONSTITUTION:An optical part 3 is constituted of a lamp 15, a lens 16, a fiber 17 and a spherical lens 7, and the lens 7 and the fiber 17 are supported by a transparent supporting plate 8. When a focus of the lens 7 is set so as to coincide with a focus F in case when an impression surface 5a has been considered to be a part of a parabolic surface, reflected rays from the impression 5 travel upward almost in parallel. Subsequently, an image is formed on the image pickup surface of a TV camera 2 by a condenser lens 1. In this case, a video signal is binary-coded by a threshold level, a signal 22 from a generator 22 is gated in a measuring range of a picture, and a pulse is measured by a counter 12.

Description

【発明の詳細な説明】 本発明はプリネル硬度針の自動読取装置に関するもので
ある。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic reading device for Purinel hardness needles.

プリネル硬度計において硬度を測定する方法は第１図に
示すように鋼球に荷重を負荷しそこにできる圧痕イ径を
光学系を用いてスクリーン上に拡大しその像の圧痕イの
縁のコントラストを人が計るために人差や疲れが大変で
ある。As shown in Figure 1, the method of measuring hardness using a Prinnell hardness tester is to apply a load to a steel ball, magnify the diameter of the indentation A formed there on a screen using an optical system, and check the contrast of the edge of the indentation A in the image. There are differences between people and fatigue due to human measurement.

そこでテレビカメラを用いて画像計測による方法が試ら
れたが試料表面はグラインダ仕上程度の粗い面をしてい
るので圧痕の縁を検出する処理が大変で実用に到らない
。Therefore, a method using image measurement using a television camera was tried, but since the sample surface has a rough surface similar to that of a grinder finish, the process of detecting the edges of the indentation is difficult and is not practical.

これは圧痕を打つ前の面を正反射法で画像を作っている
ためにグラインダでできた凹凸もコントラストとして現
われて信号の一部となっている為である。This is because the image is created using the specular reflection method on the surface before the impression is made, so the unevenness created by the grinder also appears as contrast and becomes part of the signal.

すなわち、従来は第２図に示すように光源ａからレンズ
ｂｔ介して八−フミラーＣに入射した光を試料ｄの表面
の圧痕部Ｃに当て、この圧痕部ｅからの反射光を集光レ
ンズｆを介してスクリーンｇ上に画偉りを作っていた。That is, as shown in FIG. 2, conventionally, light from a light source a enters an eight-finger mirror C via a lens bt and is directed onto an indentation C on the surface of a sample d, and the reflected light from this indentation e is passed through a condenser lens. An image was created on the screen g via f.

この場合、圧痕部・に照射される光■は圧痕面１で破線
方向に主軸をもつ散乱光となるが正反射光は多い。In this case, the light (3) irradiated onto the indented portion becomes scattered light having its principal axis in the direction of the broken line on the indented surface 1, but there is much specularly reflected light.

そｏ−＋め集光し／ズｆには一部しか入らないのでスク
リーンｇ上では暗くなる。Since only a portion of the light is focused on the 0-+ side f, it becomes dark on the screen g.

また、■の光はバージン面ｊに照射され第３図のような
反射分布となり、その内の一部が集光レンズｆを過ル結
鍬する。Further, the light (3) is irradiated onto the virgin surface j, resulting in a reflection distribution as shown in FIG. 3, and a portion of the light irradiates the condenser lens f.

そこで８／Ｊ（Ｓは圧痕面の情報、Ｎはバージン情報）
が良くない（面積が大きく違わない）。Therefore, 8/J (S is information on the indented surface, N is virgin information)
is not good (the area is not much different).

今、現想レンズ（第３図に破線で示す＞１人Ｓ れれば／Ｎは良くなると思われるがブリネル硬度針に取
付けることはできない。Currently, if the current lens (shown by the broken line in Figure 3) is used by >1 person, /N would be improved, but it cannot be attached to the Brinell hardness needle.

ブリネル硬度針では負荷軸を中空にしその中に光学系を
取付でいるので大きくすることはで色ない。With Brinell hardness needles, the load shaft is hollow and the optical system is mounted inside it, so there is no point in making it larger.

しかし、レンズ開口を大きくしなければＮが小さくなら
ないのでへは大きくならない。However, unless the lens aperture is enlarged, N cannot be reduced, and therefore .

今までは平均的なＮを記したがξクロ的に視るとＮは大
きく変動幅をもっているが、８／Ｎは極端に悪いのでビ
デオ信号を単純にしきい値でコンパレートして２値化す
ると圧痕部６以外も検出することＫなシ、正確に圧痕の
面積を計測することはできない。Up until now, I have described the average N, but from a ξchromatic perspective, N has a large fluctuation range, but 8/N is extremely bad, so the video signal is simply compared with a threshold and converted into a binary value. In this case, it is impossible to detect areas other than the indentation portion 6, and the area of the indentation cannot be accurately measured.

本発明は上記の事情に鎌みなされたものであって、その
目的とするところは集光レンズが小さくて４８への良い
画質を作ることができて簡単な画像島理系で精度の高い
計測ができＨ３値の精［を良くすることができるブリネ
ル硬度針の自動読取装置を提供することにある。The present invention has been made in consideration of the above circumstances, and its purpose is to be able to produce good image quality for 48 with a small condensing lens, and to enable highly accurate measurement using a simple image plane science system. An object of the present invention is to provide an automatic reading device for a Brinell hardness needle that can improve the accuracy of the H3 value.

以下、本発明ｆ：第４図以下を参照して説明す図面中＋
Ｆｉ集光レンズ、２ｔｉテレビカメラ、３は光学部、４
＃′ｉ試料、５は圧痕、６はスクリーンである。Hereinafter, the present invention f: In the drawings explained with reference to FIG.
Fi condensing lens, 2ti TV camera, 3 is optical section, 4
Sample #'i, 5 is an impression, and 6 is a screen.

光学部３はランプのような光源１５とレンズ１６とファ
イバ１７と球レンズ７とより構成されていて球レンズ７
と７アイパ１７とけ透明な支持板８により支持されてい
る。The optical section 3 is composed of a light source 15 such as a lamp, a lens 16, a fiber 17, and a ball lens 7.
The 7-eyeper 17 is supported by a transparent support plate 8.

図面中１０は２値回路、１１はゲート、１２は計数器、
Ｓ３はパルス信号発生器、１４は演算器、１Ｂは受像器
である。In the drawing, 10 is a binary circuit, 11 is a gate, 12 is a counter,
S3 is a pulse signal generator, 14 is an arithmetic unit, and 1B is an image receiver.

前記球レンズ７の焦点は圧痕面５ａを放物面の一部と考
えた時の焦点Ｆに一致させセットする。このことは放物
面焦点Ｆに点光源が有ると同じで圧痕５からの反射光は
ほとんど平行に上の方に進む。The focal point of the spherical lens 7 is set to match the focal point F when the indented surface 5a is considered as a part of a paraboloid. This is the same as when there is a point light source at the parabolic focal point F, and the reflected light from the indentation 5 travels upward almost in parallel.

そして、集光レンズ１でテレビカメラ２の撮像面に結像
する〇 光通路にあるファイバ６は集光レンズ１に入る一部の光
を遮断するがレンズ全体の一部でらるので影響力は非常
に少ない。Then, the condensing lens 1 forms an image on the imaging surface of the television camera 2. The fiber 6 in the optical path blocks some of the light entering the condensing lens 1, but since it is part of the entire lens, it has an influence. are very few.

得られた画像＝ｉＴＶ走査で電気信号に変換するのはテ
レビカメラ２の役目となる。The television camera 2 is responsible for converting the obtained image into an electrical signal by iTV scanning.

第５図はテレビカメラ２の画偉であり、点線で囲まれた
部分が計測範囲（マスク）である。FIG. 5 shows the image height of the television camera 2, and the area surrounded by dotted lines is the measurement range (mask).

しきい値２０でビデオ信号２１を２値化（しきい値２０
より大きい時−１１また小さい時−〇）すると白黒の像
となる。Binarize the video signal 21 with a threshold value of 20 (threshold value of 20
When it is larger - 11 and when it is smaller - ○), it becomes a black and white image.

この時、□同時に計測範囲（マスク）も決めると計測範
囲がＩで２値化信号が１であることでゲー）１作りパル
ス信号発生器１３からの信号２２をゲートすると出力は
パルスの数になるので計数器Ｉ２で計数できる。At this time, □If you also decide the measurement range (mask) at the same time, the measurement range is I and the binary signal is 1, so make 1. When you gate the signal 22 from the pulse signal generator 13, the output will be the number of pulses. Therefore, it can be counted by the counter I2.

計数値の較正は板面積の物を撮して計測範囲【作りその
計測範囲の計数をパルス信号発生器１３の発振数を変え
ることで変化させ合わせると直読できる（第６図参照）
。Calibration of the count value can be done directly by taking a photo of an object with the area of the board, determining the measurement range, and changing the count in the measurement range by changing the number of oscillations of the pulse signal generator 13 (see Figure 6).
.

すると圧痕５の面積がわかるので計算し直径ｄを求める
。Then, since the area of the indentation 5 is known, the diameter d is calculated.

投影面積んは πｄ冨 入＝　　　であるから Ｅ ｄ＝＝２　ｆ−となる。Projected area πd wealth Because input = E d==2 f-.

直径ｄからＨＢｔ−求める計算を実施する。Perform calculation to obtain HBt from the diameter d.

Ｐ ＨＢ、＝　　□ πＤ（Ｄ−誓ＦτＦ） ＨＢ：ブリネル硬度 Ｐ：負荷荷重（ＫＩ） Ｄ：鋼球の直径（謳） ｄ；圧１［５の直径（１） 本発明に係るブリネル硬度針の自動読取装置において　
４９の良い画質が得られるのであるが、その理由は次の
通りである。P HB, = □ πD (D-FτF) HB: Brinell hardness P: Applied load (KI) D: Diameter of steel ball (song) d: Diameter of pressure 1 [5 (1) Brinell hardness needle according to the present invention in the automatic reading device of
The reason for this is as follows.

（！）　　圧痕５の形状を利用することで開口の太きい
レンズを用いた時と等価な結果が得られること。(!) By utilizing the shape of the indentation 5, results equivalent to those obtained when using a lens with a wide aperture can be obtained.

（２）　　圧痕５ｔ−打つ前の表面粗さより圧痕面５ａ
の粗さが小さいので反射率が高くなり反射光の強度分布
が狭くなった。この点を利用すること。(2) Indentation 5t - Indentation surface 5a based on surface roughness before striking
Since the roughness is small, the reflectance is high and the intensity distribution of the reflected light is narrow. Take advantage of this point.

試料のバージン面２５における乱反射光強度分布２６は
第７図のようになり、圧痕面５厳における乱反射光強度
分布２７はＭ８図のようになる。The diffusely reflected light intensity distribution 26 on the virgin surface 25 of the sample is as shown in FIG. 7, and the diffusely reflected light intensity distribution 27 on the indented surface 5 is as shown in FIG. M8.

バージン面２５を拡大してみると第９図のようであり、
圧痕面５星を拡大してみると第１０図のようである。When the virgin surface 25 is enlarged, it is as shown in Fig. 9,
If you zoom in on the 5-star indentation surface, it will look like Figure 10.

バージン面２５は凹凸の直接反射光の方向を決めるので
第７図に示すごとく広範囲に広がる（散゛乱光が多くな
る）が、圧痕面５ａでは平らな部分が増加するために正
反射光が多くなる）ことになる。The virgin surface 25 determines the direction of the direct reflected light from the unevenness, so it spreads over a wide range (more scattered light) as shown in FIG. (more).

圧痕５の深さが浅い時は圧痕面５１を放物面の一部と考
えても良い。When the depth of the indentation 5 is shallow, the indentation surface 51 may be considered as part of a paraboloid.

放物面には焦点Ｆがあシ、平行光が入射すると焦点Ｆに
光は集まる。（第１１図参照）。また反対に焦点Ｆから
発光すると平行光が出て行く（第１２図参照）。A paraboloid has a focal point F, and when parallel light is incident, the light converges at the focal point F. (See Figure 11). On the other hand, when light is emitted from the focal point F, parallel light is emitted (see Fig. 12).

今一定の開口の集光レンズ１で平行入射゛と点光源での
４を比べると第１３図乃至第１５図のようになる。Now, comparing parallel incidence with a condensing lens 1 with a constant aperture and 4 with a point light source, the result is as shown in FIGS. 13 to 15.

第１３図は平行光源タイプ（従来技術）であり、第１４
図は点光源タイプ（本発明）である。Fig. 13 shows the parallel light source type (prior art), and Fig. 14 shows the parallel light source type (prior art).
The figure shows a point light source type (this invention).

平行光源タイプの場合の出力は第１５図に示す実線のよ
うになり、１＊点光源タイプの場合の出力は第１５図に
示す点線のようになり８７食値は点光源タイプの方が良
い。The output for the parallel light source type is as shown in the solid line shown in Figure 15, and the output for the 1* point light source type is as shown in the dotted line in Figure 15.The 87 eclipse value is better for the point light source type. .

本発明は以上詳述し念ようになり、圧痕面５ｍを放物面
と仮定した場合の焦点Ｆに、ファイバ６に入射された光
を球レンズ７で取出して成る点光源を設けたことを特徴
とするものである。The present invention has been described in detail above, and it is assumed that the indentation surface 5m is a paraboloid, and a point light source is provided at the focal point F, which is made by extracting the light incident on the fiber 6 with the ball lens 7. This is a characteristic feature.

したがって、集光レンズが小さくても８楡の良い画質を
作ることができるし、−が良いので簡単な画像処理系で
精度の高い計測（圧痕面積）ができるのでＨＢ値の精度
が良い。Therefore, even if the condensing lens is small, it is possible to produce a good image quality of 8 yen, and since - is good, highly accurate measurement (indentation area) can be performed with a simple image processing system, so the accuracy of the HB value is good.

また圧痕部が白いので画像としては真値より犬きくなる
傾向にあるために硬度値として低い方の誤差となるので
安全サイドの結果となる。In addition, since the indentation part is white, the image tends to be sharper than the true value, so the hardness value will have a lower error, resulting in a safer result.

【図面の簡単な説明】[Brief explanation of drawings]

第１図はプリネル硬度計において硬度を測定する一般の
方法の説明図、第２図は従来のブリネル硬度針の読取装
置の構成説明図、第３図は従来の読取装置における圧痕
面の清報８とツク−ジン面の情報Ｎとの説明図、第４図
は本発明一実施例の構成説明図、第５図はテレビ受像面
の画像の説明図、第６図は信号処理の説明図、第７図は
バージン面の乱反射光強度分布の説明図、第６図は圧痕
面の乱反射光強度分布の説明図、第９図はバージン面の
拡大図、第１０図は圧痕面の拡大図、第１１図は圧痕面
に平行光線を入射した場合の説明図、第１２図は圧痕面
の焦点に点光源を置いた場合の説明図、第１３図は平行
光源のタイプの情報８、Ｈの説明図、第１４図は点光源
タイプの情報８、Ｎの説明図、第１５図は情報Ｓ％Ｎの
説＠図である。 ５鳳は圧痕面、６はファイバ、７ｔ′ｉ球レンズ、Ｆは
焦点。 出願人　株式会社　小松製作所 代通人　弁理士米　原　正　章 弁理士浜　本　　忠 第９図 第１１図 第１０図 第１２図Figure 1 is an explanatory diagram of a general method for measuring hardness using a Prinell hardness tester, Figure 2 is an explanatory diagram of the configuration of a conventional Brinell hardness needle reader, and Figure 3 is an illustration of the indented surface of the conventional reader. FIG. 4 is an explanatory diagram of the configuration of an embodiment of the present invention, FIG. 5 is an explanatory diagram of the image on the television receiving surface, and FIG. 6 is an explanatory diagram of signal processing. , FIG. 7 is an explanatory diagram of the intensity distribution of diffusely reflected light on the virgin surface, FIG. 6 is an explanatory diagram of the intensity distribution of diffusely reflected light on the indented surface, FIG. 9 is an enlarged view of the virgin surface, and FIG. 10 is an enlarged diagram of the indented surface. , Fig. 11 is an explanatory diagram when parallel light rays are incident on the indented surface, Fig. 12 is an explanatory diagram when a point light source is placed at the focal point of the indented surface, and Fig. 13 is information 8, H on the type of parallel light source. FIG. 14 is an explanatory diagram of point light source type information 8 and N, and FIG. 15 is an explanatory diagram of information S%N. 5 is an indentation surface, 6 is a fiber, 7 is a ball lens, and F is a focal point. Applicant Komatsu Manufacturing Co., Ltd. Patent Attorney Masaaki Yonehara Patent Attorney Tadashi Hamamoto Figure 9 Figure 11 Figure 10 Figure 12

Claims (1)

【特許請求の範囲】[Claims] 圧痕面５ａｔ−放物面と仮定し九場合の焦点Ｆに、ファ
イバ６に入射された光を球レンズ７で取出して成る点光
源を設けたごと′ｆ：ｆｉＰ徴とするプリネル硬度計の
自動読取装置。Assuming that the indentation surface 5at is a paraboloid, a point light source formed by extracting the light incident on the fiber 6 with a ball lens 7 is provided at the focal point F, and the automatic Prinell hardness tester assumes the f:fiP characteristic. reading device.